If -3(y-1)=9, find the value of 1/2 y

-3(y - 1)  =  9

                          First let's solve this equation for  y . Divide both sides by  -3 .

y - 1  =  9 / -3

y - 1  =  -3

                          Add  1  to both sides of the equation.

y  =  -3 + 1

y  =  -2

Now that we know  y  =  -2  ,   we can find the value of  $\frac12$y .

$\frac12$y  =  $\frac12$(-2)

$\frac12$y  =  -1